One currently prevailing figure-guessing game is played by two persons, each of them providing the other person a "set of figure" riddle whose answer is kept by the provider. The other person will guess a figure, and his guess will be compared with the solution figure to see how many digits in the figure correspond with the digits in the solution figure. Then a hint is provided, enabling the other person to revise, time by time, his figures. The winner will be the one who gives the correct answer in a minimum time. Through this game, the player's thoughts can be trained. Moreover players can compete their intelligence with each other. Hence, this game is useful. However, this game has some demerits. Firstly, this game requires the participation of two players; in other words, an individual cannot play alone to enhance his intelligence. Secondly, it often happens that an incorrect hint is provided (due to careless mistakes); an incorrect hint will affect the proceeding of the game or even terminate it.